1-(2-Hydroxy-3-n-alkoxypropyl)-4-substituted piperidines, pharmaceutical compositions, thereof and use thereof

ABSTRACT

1-(2-Hydroxy-3-n-alkoxypropyl)-4-substituted-piperazines and piperidines and derivatives thereof useful as immune regulants are disclosed. Also disclosed are pharmaceutical compositions containing the novel compounds and a method of regulating the immune response of a subject by administration of the novel compounds.

This is a division of application Ser. No. 55,936, filed on July 9,1979, now U.S. Pat. No. 4,255,426.

BACKGROUND OF THE INVENTION

This invention relates to novel1-(2-hydroxy-3-n-alkoxypropyl)-4-substituted-piperazines and piperidinesuseful as immune regulants.

A number of compounds have been known in the art to be useful asantiinflammatory agents, for example the corticosteriods,phenylbutazone, indomethacin and various3,4-dihydro-4-oxo-2H-1,2-benzothiazine-4-carboxamide-1,1-dioxides, suchas those disclosed in U.S. Pat. No. 3,591,584. Accordingly, thesecompounds have been of therapeutic value in the treatment of arthriticand other inflammatory conditions such as rheumatoid arthritis. Suchconditions have also been treated by administration of immunoregulatoryagents, such as levamisole, as described for example in ArthritisRheumatism, 20 1445 (1977) and Lancet, 1, 393 (1976).

It is also known that biological vaccines such as Corynebacterium pavrumand BCG, a viable strain of Mycobacterium bovis, have utility as immunestimulants of the reticulo-endothelial system and are thereby capable ofincreasing the resistance of a warm-blooded animal to tumors. However,the use of these agents has been restricted by hepatic-renal toxicity,granuloma formation, neutropenia and inconsistent therapeutic effects.Accordingly, it has been of continuing interest to developnon-biological, systemically active immune stimulants for use inincreasing the resistance of a host to tumors. For discussions of thestimulation of cell-mediated immunity and antitumoral activity, seeHerberman, Ad. Cancer Res., 19, 207 (1971), Jordan and Merigan, Ann.Rev. Pharmacol., 15, 157 (1975), Levy and Wheelock, Adv. Cancer Res.,20, 131 (1972) and Sinkovics, Post Graduate Medicine, 59, 110 (1976).

SUMMARY OF THE INVENTION

The present invention relates to novel1-(2-hydroxy-3-n-alkoxypropyl)-4-substituted-piperazines and piperidineshaving immune regulant activity. More specifically, the compounds of thepresent invention are those of Formula I: ##STR1## and thepharmaceutically acceptable acid addition salts thereof, wherein R₁ isn-alkyl of 10 to 20 carbon atoms; and X is selected from the groupconsisting of: ##STR2## wherein R₂ is selected from the group consistingof hydrogen, alkyl of 1 to 3 carbon atoms, benzyl, monosubstitutedbenzyl, phenyl and monosubstituted phenyl, wherein said substituents areselected from the group consisting of chloro, bromo, fluoro, alkyl of 1to 3 carbon atoms, alkoxy of 1 to 3 carbon atoms and trifluoromethyl; R₃is selected from the group consisting of hydrogen, methyl, --CH₂ NH₂ and--CONH₂.

One group of compounds of interest is that wherein X is R₂-substituted-piperazino. Preferred compounds are those wherein R₁ isfrom 16 to 20 carbon atoms, most preferably 16 or 18 carbon atoms.Preferred substituents for R₂ are benzyl and monosubstituted benzyl, forexample 4-chlorobenzyl, 4-fluorobenzyl, 4-methylbenzyl, 4-methoxybenzyl,phenyl and monosubstituted phenyl for example 3-trifluoromethylphenyl.An especially preferred group for R₂ is benzyl.

A further group of compounds of interest is that wherein X is (R₂,R₃)-substituted-piperidino. Preferred compounds are those wherein R₁ isof 16 to 20 carbon atoms, most preferably 16 or 18 carbon atoms.Preferred substituents for R₂ are hydrogen and phenyl, including thosecompounds wherein R₃ is either hydrogen, methyl, or --CH₂ NH₂ or--CONH₂.

The present invention also includes pharmaceutical compositionscontaining the novel compounds of formula I together with apharmaceutically-acceptable carrier or diluent. Preferred pharmaceuticalcompositions are those containing the preferred novel compounds offormula I as set forth hereinabove.

Also embraced by the present invention is a method of immune regulationin a host which comprises administering to the host an effective immuneregulant amount of a compound of formula I, preferably selected from thepreferred compounds of formula I described hereinabove.

DETAILED DESCRIPTION OF THE INVENTION

The novel compounds of formula I are readily prepared by reaction of anappropriate 2,3-epoxypropyl-n-alkyl ether with a suitable substitutedpiperidine or piperazine. The 2,3-epoxypropyl-n-alkyl ether is preparedby reaction of an n-alkyl alcohol with an allyl halide, preferably allylchloride or bromide. The reaction is generally conducted in the presenceof an alkali metal hydride such as sodium hydride in an inert organicsolvent, such as dimethyl formamide, at temperatures from about 50° C.to 120° C., preferably 75°-100° C. The allyl-n-alkyl ether formed inthis reaction is then oxidized to the corresponding2,3-epoxypropyl-n-alkyl ether by conventional methods using, forexample, a peroxy acid as the oxidizing agent, for example, perbenzoicacid, m-chloro-perbenzoic acid and the like. The reaction is generallyconducted in an inert organic solvent, such as methylene chloride,chloroform, and the like at a temperature of about 10°-50° C.,preferably at about room temperature.

The 2,3-epoxypropyl-n-alkyl ether is reacted with an appropriate 1-R₂-substituted-piperazine or a 4,4-R₂ R₃ -substituted-piperidine. Thereaction is effected by heating the reactants at a temperature of about75° C. to about 250° C., preferably at about 150° to 200° C., preferablyemploying a small excess of the substituted piperazine or piperidine.The time necessary for completion of the reaction will vary with thetemperature employed but is generally from about 15 minutes to about 2hours at the preferred temperatures in the range 150° to 200° C. Thereaction is preferably conducted without the addition of a solvent, butif desired, a reaction inert solvent, such as dimethyl formamide and thelike, may be employed.

For preparation of the R₂ -substituted-piperazino compounds of thisinvention an alternative and convenient method of preparation is toreact the 2,3-epoxypropyl-n-alkyl ether with the readily available1-benzylpiperazine to form1-benzyl-4-(2-hydroxy-3-n-alkoxypropyl)-piperazine, in accord with thereaction procedures described above. The 1-benzyl group may then beremoved by hydrogenolysis, for example using a palladium on carboncatalyst and hydrogen. The reaction is generally conducted at atemperature between about 10°-50° C., preferably at about roomtemperature, in an inert organic solvent, such as an ether liketetrahydrofuran, dioxane or dimethoxyethane, or an n-alkanol of 1 to 4carbon atoms, particularly methanol or ethanol. The1-(2-hydroxy-3-n-alkoxypropyl)-piperazine (i.e. where R₂ is hydrogen)formed in this manner can then be further reacted to form thosecompounds having other R₂ groups. Thus, for example, the1-(2-hydroxy-3-n-alkoxypropyl)-piperazine may be reacted with anappropriately substituted benzyl halide in the presence of a base, forexample a trialkyl amine such as triethylamine. The reaction isgenerally conducted in an inert organic solvent, for example an ethersuch as tetrahydrofuran, dioxane, dimethoxyethane and the like, attemperatures in the range of about 50°-150° C., preferably at refluxtemperature of the solvent. Compounds where R₂ is alkyl may be preparedby reaction of 1-(2-hydroxy-3-n-alkoxypropyl)-piperazine with anappropriate alkyl halide using the reaction conditions described abovefor reaction of a benzyl halide.

Preparation of the (R₂,R₃)-substituted-piperadino compounds of thisinvention wherein R₃ is aminomethyl is effected by reaction of theappropriate 4-R₂ -4-cyano-piperidine with the appropriate2,3-epoxypropyl-n-alkyl ether as described above to form the4-cyano-1-(2-hydroxy-3-n-alkoxypropyl)-4-R₂ -piperidine. The 4-cyanogroup is then readily reduced to aminomethyl, for example with Raneynickel and hydrogen. The reaction is effected at a temperature of about40°-140° C. in an inert organic solvent such as an ether liketetrahydrofuran, dioxane, dimethoxyethane and similar solvents.

Preparation of the (R₂,R₃)-substituted-piperidine compounds wherein R₃is a carboxamide group is effected by reaction of the appropriate2,3-epoxypropyl-n-alkyl ether with an R₂-substituted-4-carboxamidopiperidine using the reaction methodsdescribed above. If desired, the4-carboxamido-1-(2-hydroxy-3-n-alkoxypropyl)-piperidine may be employedas an intermediate for the preparation of the corresponding4-aminomethyl-substituted compounds by reduction of the 4-carboxamidogroup with a metal hydride, such as lithium aluminum hydride or sodiumbis(2-methoxyethoxy)aluminum hydride and the like, generally at atemperature between about 25°-100° C. in an inert organic solvent suchas benzene, toluene, xylene and the like.

The pharmaceutically acceptable acid addition salts of the novelsubstituted piperazines and piperidines of formula I are readilyprepared by contacting the free base with the appropriate mineral ororganic acid in either aqueous solution or in a suitable organicsolvent, for example a lower alkanol having from 1 to 6 carbon atoms.The solid salt may then be obtained by precipitation or by evaporationof the solvent. The pharmaceutically acceptable acid addition salts ofthis invention include, but are not limited to, the hydrochloride,hydrobromide, hydroiodide, sulfate, bisulfate, nitrate, phosphate,acetate, lactate, maleate, fumarate, oxalate, citrate, tartrate,succinate, gluconate, methanesulfonate, and the like.

The novel compounds of this invention and their pharmaceuticallyacceptable acid addition salts are useful regulants of the immuneresponse in warm-blooded animals. These compounds are therefore usefulin the treatment of conditions such as rheumatoid arthritis and otherdiseases associated with immune deficiency and accompanied byinflammation. Like the known compound Levamisole, presently a preferredcompound for the treatment of rheumatoid arthritis, the compounds of thepresent invention act to regulate the immune response of the subject andthereby alleviate the underlying immune disorder by maintaining immunecompetence. In addition, the activity of the present novel compounds asimmune regulants makes them useful in maintaining the immune response ofa warm-blooded animal to increase the resistance of the subject totumors, the compounds acting to stimulate the natural immune system ofthe subject to reject tumors.

The present invention therefore also embraces a method of immuneregulation in a warm-blooded animal by administering to the subject aneffective immune regulant amount of a compound of the present inventionof formula I or a pharmaceutically acceptable acid addition saltthereof. In accord with this method, the compounds of the presentinvention may be administered to the subject in need of treatment byconventional routes, such as orally or parenterally, dosages in therange of about 0.10 to about 75 mg/kg body weight of the subject perday, preferably about 0.15 to about 15 mg/kg body weight per day beingsuitable. However, the optimum dosage for the individual subject beingtreated will be determined by the person responsible for treatment,generally smaller doses being administered initially and thereaftergradual increments made to determine the most suitable dosage. This willvary according to the particular compound employed and with the subjectbeing treated. In this regard, the immune competence of the subjectbeing treated may be monitored following administration usingconventional techniques employed in the art and the response of thesubject determined.

The compounds of this invention may be used in pharmaceuticalpreparations containing the compound or a pharmaceutically acceptableacid addition salt thereof in combination with a pharmaceuticallyacceptable carrier or diluent. Suitable pharmaceutically acceptablecarriers include inert solid fillers or diluents and sterile aqueous ororganic solutions. The active compound will be present in suchpharmaceutical compositions in amounts sufficient to provide the desireddosage amount in the range described above. Thus, for oraladministration the compounds may be combined with a suitable solid orliquid carrier or diluent to form capsules, tablets, powders, syrups,solutions, suspensions and the like. The pharmaceutical compositionsmay, if desired, contain additional components such as flavorants,sweeteners, excipients and the like. For parenteral administration thecompounds may be combined with sterile aqueous or organic media to forminjectable solutions or suspensions. For example, solutions of thecompounds of formula I in sesame or peanut oil, aqueous propylene glycoland the like may be used, as well as aqueous solutions or water solublepharmaceutically acceptable acid addition salts of the compounds. Theinjectable solutions prepared in this manner may then be administeredintraveneously, interperitoneally, subcutaneously or intramuscularly,with intraveneous and interperitoneal administration being preferred.

The immune regulant activity of the compounds of the present inventionmay be determined by such standard pharmacological tests as thestimulation in vitro of lymphocyte proliferation of murine thymus cellscultured in the presence of Concanavalin A (Con A) employing the generalevaluation procedure of V. J. Merluzzi et al., see Journal of Clinicaland Experimental Immunology, Volume 22, page 486 (1975). In this study,three different levels of peak lymphocyte stimulation assay (LSA)activity were established for the compounds undergoing evaluation, viz.,those equal to Con A alone; those superior to Con A activity but lessthan levamisole, the standard compound of choice in this area; and thosehaving an activity equal to levamisole. Compounds are considered to beactive for the present purposes if they are superior to Concanavalin A.

The immune regulant activity of the compounds of the present inventionmay also be determined by an assessment of tumor rejection in, forexample, the sarcoma 180 J model. In this test, the increased life span(% ILS) is determined for a group of female CD-1 mice (20-25 g). Themice receive 10⁶ S-180 J cells which are 5 to 8 days old, byintraperitoneal administration. On the day following tumor inoculationthe mice receive 0.1 ml of the test compound formulated inTween-glycerol at the desired dose level and are then observed untildeath or for 40 days, whichever occurs first. The increased life span isthen determined from the ratio of the mean survival time of drug treatedmice to the mean survival time of untreated control group mice.

The present invention is illustrated by the following examples. However,it should be understood that the invention is not limited to thespecific details of these examples.

EXAMPLE 1 Allyl-n-hexadecylether:

n-Hexadecanol (24.2 g, 0.1 mol) was added to a suspension of sodiumhydride (9.6 g of a 50% dispersion in mineral oil, 0.2 mol) indimethylformamide (200 ml) and heated to 50° C. for 30 minutes. Allylbromide (24.2 g, 0.2 mol) was then added and the mixture heated to 90°C. for 5 hours. The reaction was cooled, diluted with a solution ofsaturated sodium chloride (300 ml), and extracted with ether (2×300 ml).The combined ether extracts were washed with a saturated solution ofsodium chloride (200 ml), filtered, dried over magnesium sulfate,treated with activated charcoal, filtered, and evaporated under reducedpressure to an oil. The resulting oil was purified by absorbing it onsilica gel, placing the silica gel in a sintered glass filter, andeluting the product off with hexane (7×200 ml) followed by toluene(4×200 ml). Concentration yielded the pure ether (14 g, 50% yield): NMR(CDCl₃) 3.40 (t, 2, --CH₂ --O--CH₂ CH═CH₂), 3.92 (d, 2, --O--CH₂CH═CH₂), 4.95-5.38 (m, 2, ═CH₂) and 5.58-6.20 (m, 1, --CH═CH₂).

EXAMPLE 2 2,3-Epoxypropyl-n-hexadecylether

Allyl-n-hexadecylether (37 g, 0.13 mol) was dissolved in methylenechloride (200 ml) and treated with m-chloro-perbenzoic acid (31 g, 0.18mol) at room temperature for 16 hours. More m-chloroperbenzoiz acid (2.0g, 0.01 mol) was added and the mixture stirred an additional 16 hours.The mixture was then filtered, treated with a saturated solution ofsodium sulfite, and stirred for 2 hours. The methylene chloride layerwas separated, washed with a saturated solution of sodium bicarbonate(4×500 ml) and water (500 ml), dried over magnesium sulfate, filteredand concentrated under reduced pressure to the desired epoxide, whichsolidified on cooling (35 g, 92% yield): mp 30°-31.5° C.; NMR (CDCl₃)1.3 (S, 28, aliphatic methylene), 2.55 (d of d, 1, epoxide), 2.73 (t, 1,epoxide) and 3.03 (m, 1, epoxide).

EXAMPLE 3 1-Benzyl-4-(2-hydroxy-3-n-hexadecyloxypropyl)piperazine

2,3-Epoxypropyl-n-hexadexylether (2.0 g, 0.0067 mol) and1-benzylpiperazine (2.03 g, 0.011 mol) were combined and heated to 180°C. for 20 minutes. The resulting mixture was dissolved in acetone andcooled in a dry ice/acetone bath. The solids that formed were filtered,dissolved in ether, and treated with gaseous hydrochloric acid. Thedesired amine hydrochloride was obtained by concentrating the ethersolution and recrystallizing the resulting solid from isopropyl alcohol(0.8 g, 13% yield): mp 237°-238° C.; NMR [(CD₃)₂ SO] 1.32 (S, 28,aliphatic methylene) and 4.55 (S, 2, Ph-CH₂ -N);

Anal: Calcd for C₃₀ H₅₄ O₂ N₂.2HCl.1/2H₂ O: C, 64.72; H, 10.32; N, 5.03;Found: C, 64.87; H, 10.22; N, 5.00.

EXAMPLE 4 1-(2-Hydroxy-3-n-hexadecyloxypropyl)-piperazine

1-Benzyl-4-(2-hydroxy-3-n-hexadecyloxypropyl)-piperazine hydrochloride(8 g, 0.0146 mol) was dissolved in toluene (100 ml), methanol (100 ml)and tetrahydrofuran (700 ml) and divided into three 300 ml portions.Each portion was hydrogenated overnight at room temperature on a Parrshaker using a 10% palladium on carbon catalyst (2 g) and 50 p.s.i.g.hydrogen. The catalyst was filtered off and the filtrate evaporatedunder reduced pressure to a solid, which was triturated under acetoneand filtered to give a total yield of product of 2.9 g (43%), mp 230° C.(dec).

Anal: Calcd for C₂₃ H₄₈ O₂ N₂.2HCl: C, 60.37; H, 11.01; N, 6.12. Found:C, 60.26; H, 10.71; N, 5.97.

EXAMPLE 51-(3,4-Dichlorobenzyl)-4-(2-hydroxy-3-n-hexadecyloxypropyl)-piperazine

1-1(2-Hydroxy-3-n-hexadecyloxypropyl)-piperazine (0.7 g, 0.0015 mol),3,4-dichlorobenzylchloride (0.328 g, 0.00168 mol) and triethylamine(1.39 ml, 0.01 mol) were refluxed in tetrahydrofuran (50 ml) for 16hours. The mixture was cooled, diluted with water (200 ml) and extractedwith ether (200 ml). The ether extract was washed with water (2×100 ml),dried over magnesium sulfate, filtered and concentrated under reducedpressure. The resulting oil was purified by silica gel chromatography(eluted with 5% ethanol in toluene), converted to the hydrochloride saltand recrystallized from hot isopropyl alcohol to give pure product (0.35g, 38% yield): mp 236°-237° C.

Anal: Calcd for C₃₀ H₅₂ O₂ N₂ Cl₂.2HCl: C, 58.44; H, 8.83; N, 4.54.Found: C, 58.06; H, 8.90; N, 4.48.

EXAMPLE 6 1-Methyl-4-(2-hydroxy-n-hexadecyloxypropyl)-piperazine

Following the procedures of Example 3, 2,3-epoxypropyl-n-hexadecyletherwas reacted with 1-methylpiperazine to form1-methyl-4-(2-hydroxy-n-hexadecyloxypropyl)-piperazine, mp 209°-211° C.

Anal: Calcd for C₂₄ H₅₀ O₂ N₂.2HCl.1/2H₂ O: C, 59.98; H, 11.12; N, 5.82.Found: C, 59.80; H, 10.88; N, 5.70.

EXAMPLE 7 1-Benzyl-4-(2-hydroxy-3-n-octadecyloxypropyl)-piperazine

Following the procedure of Examples 1 to 3,2,3-epoxypropyl-n-octadecylether and 1-benzylpiperazine were reacted toform 1-benzyl-4-(2-hydroxy-3-n-octadecyloxypropyl)-piperazine, mp235°-236° C.

Anal: Calcd for C₃₂ H₅₈ O₂ N₂.2HCl.3/4H₂ O: C, 65.23; H, 10.52; N, 4.75.Found: C, 65.39; H, 10.26; N, 4.75.

EXAMPLE 81-(4-Chlorobenzyl)-4-(2-hydroxy-3-n-hexadecyloxypropyl)piperazine

Following the procedure of Example 5,1-(2-hydroxy-3-n-hexadecyloxypropyl)-piperazine was reacted with4-chlorobenzylchloride to form1-(4-chlorobenzyl)-4-(2-hydroxy-3-n-hexadecyloxypropyl)-piperazine, mp237°-239° C.

Anal: Calcd for C₃₀ H₅₃ O₂ N₂ Cl.2HCl.1/4H₂ O: C, 61.42; H, 9.53; N,4.78. Found: C, 61.39; H, 9.10; N, 4.75.

EXAMPLE 91-(4-Methylbenzyl)-4-(2-hydroxy-3-n-hexadecyloxypropyl)-piperazine

Following the procedure of Example 5,1-(2-hydroxy-3-n-hexadecyloxypropyl)-piperazine was reacted with4-methylbenzyl chloride to form1-(4-methylbenzyl)-4-(2-hydroxy-3-n-hexadecyloxypropyl)-piperazine, mp238°-239° C.

Anal: Calcd for C₃₁ H₅₆ O₂ N₂.2HCl.3/4HCl: C, 64.73; H, 10.42; N, 4.87.Found: C, 64.75; H, 10.36; N, 4.96.

EXAMPLE 101-(3-Trifluoromethylbenzyl)-4-(2-hydroxy-3-n-hexadecyloxypropyl)-piperazine

Following the procedure of Example 5,1-(2-hydroxy-3-n-hexadecyloxypropyl)-piperazine was reacted with3-(trifluoromethyl)benzyl chloride to form1-(3-trifluoromethylbenzyl)-4-(2-hydroxy-3-n-hexadecyloxypropyl)-piperazine,mp 133°-135° C.

Anal: Calcd for C₃₀ H₅₁ O₂ N₂ F₃.HCl: C, 63.75; H, 9.27; N, 4.96. Found:C, 63.62; H, 9.13; N, 4.87.

EXAMPLE 111-(4-Fluorobenzyl)-4-(2-hydroxy-3-n-hexadecyloxypropyl)-piperazine

Following the procedure of Example 5,1-(2-hydroxy-3-n-hexadecyloxypropyl)-piperazine was reacted with4-fluorobenzyl chloride to form1-(4-fluorobenzyl)-4-(2-hydroxy-3-n-hexadecyloxypropyl)-piperazine, mp242° C. (dec).

Anal: Calcd for C₃₀ H₅₃ O₂ N₂ F.2HCl.1/4H₂ O: C, 63.20; H, 9.81; N,4.91.

EXAMPLE 121-(4-Methoxybenzyl)-4-(2-hydroxy-3-n-hexadecyloxypropyl)-piperazine

Following the procedure of Example 5,1-(2-hydroxy-3-n-hexadecyloxypropyl)-piperazine was reacted with4-methoxybenzyl chloride to form1-(4-methoxybenzyl)-4-(2-hydroxy-3-n-hexadecyloxypropyl)-piperazine, mp233°-245° C.

Anal: Calcd for C₃₁ H₅₆ O₃ N₂ 2HCl.1/4H₂ O: C, 63.95; H, 10.13; N, 4.81.Found: C, 63.74; H, 9.88; N, 4.78.

EXAMPLE 13 1-Benzyl-4-(2-hydroxy-3-n-dodecyloxypropyl)-piperazine

Following the procedures of Examples 1 to 3,2,3-epoxypropyl-n-dodecylether and 1-benzylpiperazine were reacted toform 1-benzyl-4-(2-hydroxy-3-n-dodecyloxypropyl)-piperazine, mp239°--239° C. (dec).

Anal: Calcd for C₂₆ H₄₆ O₂ N₂.2HCl: C, 63.53; H, 9.84; N, 5.70. Found:C, 63.88; H, 9.23; N, 5.63.

EXAMPLE 141-(4-Fluorobenzyl)-4-(2-hydroxy-3-n-dodecyloxypropyl)-piperazine

Following the procedures of Examples 4 and 5,1-benzyl-4-(2-hydroxy-3-n-dodecyloxypropyl)-piperazine was converted to1-(2-hydroxy-3-n-dodecyloxypropyl)-piperazine by hydrogenolysis using apalladium on carbon catalyst. The hydrogenolysis product was reactedwith 4-fluorobenzyl chloride to form1-(4-fluorobenzyl)-4-(2-hydroxy-3-n-dodecyloxypropyl)-piperzaine, mp243°-245° C.

Anal: Calcd for C₂₆ H₄₅ O₂ N₂ F.2HCl.H₂ O: C, 59.19; H, 9.36; N, 5.31.Found: C, 59.35; H, 9.25; N, 5.79.

EXAMPLE 15 1-Phenyl-4-(2-hydroxy-3-n-hexadecyloxypropyl)-piperazine

Following the procedure of Example 3, 2,3-epoxypropyl-n-hexadecyletherand 1-phenylpiperazine were reacted to form1-phenyl-4-(2-hydroxy-3-n-hexadecyloxypropyl)-piperazine, mp 195°-196°C.

Anal: Calcd for C₂₉ H₅₂ O₂ N₂.2HCl: C, 65.27; H, 10.20; N, 5.25. Found:C, 65.58; H, 9.99; N, 5.45.

EXAMPLE 16 1-Benzyl-4-(2-hydroxy-3-benzyloxypropyl)-piperazine

Following the procedure of Example 3, 2,3-epoxypropylbenzyl ether and1-benzylpiperazine were reacted to form the title compound; mp 215°-216°C.

Anal: Calcd for C₂₁ H₂₈ O₂ N₂.2HCl: C, 61.02; H, 7.31; N, 6.78. Found:C, 60.48; H, 7.20; N, 6.75.

EXAMPLE 174-Cyano-1-(2-hydroxy-3-n-hexadecyloxypropyl)-4-phenylpiperidine

4-Cyano-4-phenylpiperidine (1.1 g, 0.0059 mol) and2,3-epoxypropyl-n-hexadecylether (1.6 g, 0.0056 mol) were combined andheated to 185° C. for 30 minutes. After cooling, ethyl acetate (20 ml)and acetonitrile (20 ml) were added, and the resulting solid wascollected by filtration (1.6 g, 62% yield): mp 69°-70° C.; ir (KBr) 2227cm⁻¹.

EXAMPLE 184-Aminomethyl-1-(2-hydroxy-3-n-hexadecyloxypropyl)-4-phenylpiperidinehydrochloride

4-Cyano-1-(2-hydroxy-3-n-hexadecyloxypropyl)-4-phenylpiperidine (1.5 g,0.003 mol) was dissolved in a mixture of tetrahydrofuran (50 ml) andethanol (3 ml) saturated with ammonia. Raney-nickel (0.8 g) was added,and the mixture was hydrogenated at 50 psi (H₂) for 2 hours. The mixturewas then filtered and concentrated under reduced pressure to a waxysolid. This solid was dissolved in methylene chloride, treated withgaseous hydrochloric acid and again concentrated to a solid. The pureproduct was obtained by recrystallization from isopropyl alcohol (1.0 g,59% yield): mp 227°-228° C.

Anal: Calcd for C₃₁ H₅₆ O₂ N₂ 2HCl: C, 66.29; H, 10.41; N, 4.99. Found:C, 66.18; H, 10.40; N, 5.18.

EXAMPLE 194-Aminomethyl-1-(2-hydroxy-3-n-octadecyloxypropyl)-4-phenylpiperidine

Following the procedure of Examples 17 and 18,4-cyano-4-phenylpiperidine was reacted with2,3-epoxypropyl-octadecylether and reduced to form4-aminomethyl-1-(2-hydroxy-3-n-octadecyloxypropyl)-4-phenylpiperidine,mp 223°-224° C.

Anal: Calcd for C₃₃ H₆₀ O₂ N₂.2HCl.2.25H₂ O: C, 62.88; H, 10.63; N,4.44. Found: C, 62.96; H, 10.25; N, 4.56.

EXAMPLE 20 4-Carboxamido-1-(2-hydroxy-3-n-hexadecyloxypropyl)-piperidine

Isonipecotinamide (0.7 g, 0.0055 mol) and2,3-epoxypropyl-n-hexadecylether (1.49 g, 0.005 mol) were combined andheated to 180° C. for 20 minutes. The reaction mixture was cooled, ethylacetate (20 ml) added, and the resulting solids isolated by filtration.Recrystallization from hot ethyl acetate (15 ml) gave pure product (1.6g, 75% yield): mp 97°-98° C.; ir (KBr) 1653 cm⁻¹.

Anal: Calcd for C₂₅ H₅₀ O₃ N₂ : C, 70.37; H, 11.81; N, 6.57. Found: C,69.90; H, 11.42; N, 6.50.

EXAMPLE 21 4-Aminomethyl-1-(2-hydroxy-3-n-hexadecyloxypropyl)-piperidinehydrochloride

4-Carboxamido-1-(2-hydroxy-3-n-hexadecyloxypropyl)-piperidine, (1.1 g,0.0026 mol) was dissolved in toluene (20 ml) and a 70% solution ofsodium bis-(2-methoxyethoxy)aluminum hydride (3.5 ml) was slowly addedover 15 minutes. The reaction mixture was heated to 80° C. for 16 hoursand worked up by dropwise addition of ethyl acetate (10 ml) and thenwater (20 ml), followed by extraction with ether (50 ml). The etherextract was washed with water (2×50 ml), dried over magnesium sulfate,filtered, converted to the hydrochloride salt, and concentrated to asolid under reduced pressure. Pure product (0.25 g, 20% yield) wasobtained by recrystallization from hot isopropyl alcohol/acetone (1/1):mp 202° C. (dec).

Anal: Calcd for C₂₅ H₅₂ O₂ N₂.2HCl.3/4H₂ O: C, 60.16; H, 11.20; N, 5.61.Found: C, 60.23; H, 10.53; N, 5.55.

EXAMPLE 22 1-(2-Hydroxy-3-n-hexadecyloxypropyl)-4-phenylpiperidine

4-Phenylpiperidine (1.8 g, 0.011 mol) and2,3-epoxypropyl-n-hexadecylether (2.98 g, 0.01 mol) were combined andheated to 180° C. for 30 minutes. The reaction mixture was cooled,acetone was added, and the mixture was stirred for 16 hours. Theresulting solids were collected and recrystallized from hot acetone togive pure product (2.3 g, 50% yield): mp 64°-65° C.

Anal: Calcd for C₃₀ H₅₃ O₂ N: C, 78.37; H, 11.62; N, 3.05. Found: C,78.64; H, 11.42; N, 3.26.

EXAMPLE 23 1-(2-Hydroxy-3-n-octadecyloxypropyl)-4-phenylpiperidine

Following the procedure of Example 22, 2,3-epoxypropyl-n-octadecyletherwas reacted with 4-phenylpiperidine to give1-(2-hydroxy-3-n-octadecyloxypropyl)-4-phenylpiperidine, mp 170°-171° C.

Anal: Calcd for C₃₂ H₅₇ O₂ N.HCl: C, 73.31; H, 11.15; N, 2.67. Found: C,73.57; H, 10.95; N, 2.54.

EXAMPLE 24 4-Methyl-1-(2-hydroxy-3-n-hexadecyloxypropyl)-piperidine

Following the procedure of Example 22, 2,3-epoxypropyl-n-hexadecyletherwas reacted with 4-methylpiperidine to form4-methyl-1-(2-hydroxy-3-n-hexadecyloxypropyl)-piperidine, mp 84°-85° C.

Anal: Calcd for C₂₅ H₅₁ O₂ N.HCl.1/4H₂ O: C, 68.45; H, 12.06; N, 3.19.Found: C, 68.58; H, 12.28; N, 3.09.

EXAMPLE 25 Sarcoma 180J Model for Assessment of Tumor Rejection

Six female CD-1 mice (20-25 g) per group received 10⁶ S-180J cells whichwere 5 to 8 days old by intraperitoneal administration. On the dayfollowing tumor innoculation the mice received 0.1 ml of the testcompound formulated in the fat emulsion vehicle Intralipid (CutterLaboratories) by dissolving the drug in a minimum amount of alcohol andadding this solution to the Intralipid at the desired dose and were thenobserved until death or 40 days, whichever occurs first. Results areexpressed as increased percent life span (%ILS), defined as follows:##EQU1## Where S=Mean Survival time of Drug Treated Mice; and Sc=MeanSurvival time of Control Mice.

Results obtained by the above test procedure were as follows:

    ______________________________________                                        Example       % ILS   Dose (mg/kg)                                            ______________________________________                                        3             64      1                                                       4             73      15                                                      6             54      64                                                      10            28      15                                                      11            25      75                                                      13            89      75                                                      14            26      0.6                                                     16            27      15                                                      18            78      16                                                      19            88      15                                                      20            115     16                                                      ______________________________________                                    

EXAMPLE 26

The immune regulant activity of the compounds of Examples 3, 5, 7, 9,11, 13, 14, 15 and 16 was evaluated by determining their ability tostimulate, in vitro the lymphocyte proliferation of murine thymus cellscultured in the presence of Concanavalin A (Con A) by employing theprocedure of V. J. Merluzzi et. al., as essentially described in theJournal of Clinical and Experimental Immunology, Vol. 22, p. 486 (1975).The cells were derived from male C57B1/6 mice of from 6-8 weeks age,purchased from the Jackson Laboratories of Bar Harbor, Me. and the Con Awas obtained from Sigma Chemicals of St. Louis, Mo. Each cell culture(consisting of 0.10 ml thymus cells stock solution, 0.05 ml of Con Astock solution and 0.05 ml of drug solution) was performed inquadruplicate and cellular proliferation was measured, after 48 hours ofincubation at 37° C., by pulsing each culture with ³ H-thymidine (0.01ml of specific activity 1.9 C.mM, obtained from Schwarz-Mann, Inc. ofOrangeburg, N.Y.) and then determining the incorporation of ³H-thymidine into cellular desoxyribonucleic acid (DNA) by an assessmentof radioactivity using a liquid scintillation counter. The resultsobtained in this manner are expressed quantitatively in terms of theaverage counts per minute (cpm) of ³ H-thymidine incorporated at eachdrug level. On this basis, three different levels of peack activity wereestablished in the present lymphocyte stimulation assay (LSA) and theseare defined in the manner hereinafter indicated, viz., those levelsequal to Con A alone (6,000±300 cpm) were assigned a negative value orscore of zero; those superior (10,000±700 cpm) to Con A activity butless than levamisole were scored as +; while those equal to levamisole(30,000±900 cpm) were scored as ++ Minimum effective concentrations(MEC) were determined at activity levels with a score of +.

    ______________________________________                                        Peak Activity                                                                 Example  Activity Level                                                                            Drug Concentration (μg/ml)                            ______________________________________                                        3        +           0.10                                                     5        +           1.0                                                      7        +           0.01                                                     9        +           0.01                                                     11       +           0.30                                                     13       +           0.30                                                     14       +           0.10                                                     15       +           0.30                                                     16       + +         0.04                                                     Levamisole                                                                             + +         28                                                       ______________________________________                                        Potency at + Activity Level                                                   Example       MEC (μg/ml)                                                  ______________________________________                                        3             0.004                                                           5             0.10                                                            7             <0.004                                                          9             <0.004                                                          11            0.04                                                            13            <0.004                                                          14            0.10                                                            15            0.004                                                           16            <<0.004                                                         Levamisole    1.0                                                             ______________________________________                                    

I claim:
 1. A compound of the formula ##STR3## and the pharmaceuticallyacceptable acid addition salts thereof, wherein R₁ is n-alkyl of 10 to20 carbon atoms; and X is ##STR4## wherein R₂ is selected from the groupconsisting of hydrogen, alkyl of 1 to 3 carbon atoms, benzyl,monosubstituted benzyl, phenyl and monosubstituted phenyl, wherein saidsubstituents are selected from the group consisting of chloro, bromo,fluoro, alkyl of 1 to 3 carbon atoms and alkoxy of 1 to 3 carbon atoms;and R₃ is selected from the group consisting of hydrogen, methyl, --CH₂NH₂ and --CONH₂.
 2. A compound of claim 1 wherein R₁ is n-alkyl of 16 to20 carbon atoms.
 3. A compound of claim 1 wherein R₂ is phenyl.
 4. Acompound of claim 3 wherein R₁ is n-alkyl of 16 carbon atoms.
 5. Acompound of claim 4 wherein R₃ is hydrogen.
 6. A compound of claim 4wherein R₃ is methyl.
 7. A compound of claim 4 wherein R₃ is --CH₂ NH₂.8. A compound of claim 3 wherein R₁ is n-alkyl of 18 carbon atoms.
 9. Acompound of claim 8 wherein R₃ is hydrogen.
 10. A compound of claim 8wherein R₃ is --CH₂ NH₂.
 11. A compound of claim 1 wherein R₂ ishydrogen.
 12. A compound of claim 1 wherein R₁ is n-alkyl of 16 carbonatoms.
 13. A compound of claim 12 wherein R₃ is --CONH₂.
 14. A compoundof claim 12 wherein R₃ is --CH₂ NH₂.
 15. A pharmaceutical compositioncomprising an immune-regulant effective amount of a compound of claim 1and a pharmaceutically acceptable carrier.
 16. A method of immuneregulation in a host which comprises administering to said host aneffective immune regulant amount of a compound of claim 1.